On a four-state tour, Obama implored Democratic voters to show up in large numbers. Polls suggest his party will lose the House of Representatives to the Republicans and see its Senate majority weakened.

"Unless each and every one of you turn out and get your friends to turn out and get your families to turn out, then we could fall short and lose all the progress that we've made over the last couple of years to avoid the apocalypse," Obama told somber campaign volunteers at his first stop in Philadelphia.

In his hometown of Chicago, a crowd that Democrats said was over 3,000 people held signs, one saying "Obama Yes" and the other, "Apocalypse NO." "We've got a lot of work to do, not only to move the earth out of the path of the doomsday asteroid, but to make sure that we stay out of the way," Obama told the intimate group.

“Our technology is still too backward to consider moving the path of the asteroid, but we can move the Earth out of the way” Obama said, without specifying the exact method he was referring to.

Democrats are facing voter discontent over an ailing economy and persistently high unemployment. But Obama pointed out the futility of such matters if the world ends in 2012. “Employment? Food? Energy? What does it all mean if the end is near?" Obama implored.

Republicans have scored points by attacking Obama's agenda, including the health care overhaul and huge economic stimulus plan, that they call a government ‘over-the-edge-into-the-abyss’ move. Loss of the House could stall Obama's legislative efforts to stop the end of the world.

Representative John Boehner, who would become Speaker of the House if Republicans win a majority, said Obama's agenda had not fixed the country's economic problems. “All this talk of averting the earth and avoiding the Apocalypse is total hogwash,” Boehner insisted. “If God wants to destroy the world, then nothing can stop it. So let's stick to more pressing issues.”

Heckled

Obama is battling an "enthusiasm void," with polls showing Republicans more likely to vote than Democrats. Liberals, who helped sweep Obama to victory in the 2008 election, have complained about the lack of results, such as ending the wars in Iraq and Afghanistan, closing the Guantanamo military prison, and reforming immigration. Indeed, not even the promised lowering of the Earth's ocean levels has occurred.

At a rally in Bridgeport, Connecticut, Obama was heckled by AID activists, chanting "Stop global AID," the latest of several such protests at campaign events. This crowd, which Democrats estimated at 9,000, drowned them out, with a single vuvuzela, or perhaps a penny-whistle. However, forced off script, an exasperated Obama urged the hecklers to redirect their protests at the doomsday asteroid, which he said had no interest in funding for AID.

"We're in a difficult election," Obama said in Philadelphia. "This election is not just going to set the stage for the next two years. It's going to be a question of life or death come 2012."